Injecting Environment Variables in HTML Using EJS

Introduction

EJS (Embedded JavaScript) is a simple and easy-to-use templating language that lets you generate HTML markup with plain JavaScript. One of the common use cases for EJS is injecting environment variables into your HTML. This can be particularly useful for configuring your application at runtime without hardcoding values into your source code.

In this guide, we will cover the common questions and scenarios regarding injecting environment variables in HTML using EJS.

Open Table of Contents

What are Environment Variables?
Why Use EJS for Injecting Variables?
How to Inject Environment Variables in EJS?
Common Pitfalls
Conclusion
FAQs

What are Environment Variables?

Environment variables are key-value pairs that are used to store configuration settings and other information about the environment in which an application is running. They are commonly used to store sensitive information like API keys, database URLs, and other configuration settings that you don’t want to hardcode into your application.

Why Use EJS for Injecting Variables?

EJS is a flexible and easy-to-use templating language that integrates seamlessly with Node.js applications. It allows you to embed JavaScript code into your HTML, which means you can easily inject environment variables or any other dynamic content into your HTML pages.

How to Inject Environment Variables in EJS?

Injecting environment variables in EJS is straightforward. You can pass the environment variables to your EJS template when rendering it. Here’s a basic example:

// Assuming you are using Express.js
app.get('/', (req, res) => {
  res.render('index', { 
    envVar: process.env.YOUR_ENV_VARIABLE 
  });
});

In your EJS template, you can then access the variable like this:

<!DOCTYPE html>
<html>
<head>
  <title>My App</title>
</head>
<body>
  <h1>Environment Variable:</h1>
  <p><%= envVar %></p>
</body>
</html>

Common Pitfalls

Variable Not Defined: Ensure that the environment variable is defined in your environment. You can check this by logging process.env to the console.
Syntax Errors: Be careful with the EJS syntax. Remember to use <%= %> to output the value of the variable.
Escaping: EJS automatically escapes variables to prevent XSS attacks. If you need to output raw HTML, you can use <%- %>, but be careful with untrusted content.

Conclusion

Injecting environment variables in HTML using EJS is a powerful way to configure your application at runtime. By following the best practices and being aware of the common pitfalls, you can effectively use EJS to create dynamic and configurable HTML pages.

FAQs

Q1: Can I use EJS with any web framework?
A1: EJS is primarily used with Node.js and Express.js, but it can be used with any web framework that supports server-side rendering.

Q2: Are environment variables secure?
A2: Environment variables are more secure than hardcoding values in your source code, but they are not completely secure. Be cautious about what information you store in environment variables.

Q3: Can I pass multiple environment variables to EJS?
A3: Yes, you can pass as many environment variables as you need to your EJS template by including them in the render method.